1. Field
Various embodiments of the present disclosure relate to a nano structure, a fabrication method thereof, and application device thereof.
2. Description of the Related Art
Nano structures exhibit characteristics such as the quantum confinement effect, the Hall-Petch effect, dropping melting point, resonance phenomenon, excellent carrier mobility and so forth as compared, to conventional bulk and thin film-type structures. For this reason, nano structures are being applied to chemical batteries, solar cells, semiconductor devices, chemical sensors, photoelectric devices and the like.
Nano structures are fabricated in a top-down method or a bottom-up method. The bottom-up method includes a vapor-liquid-solid growth method and liquid growth method. The vapor-liquid-solid growth method is based on a catalytic reaction, such as the Thermal Chemical Vapor Deposition (thermal-CVD) method, the Metal-Organic Chemical Vapor Deposition (MOCVD) method, the Pulsed Laser Deposition (PLD) method, and the Atomic Layer Deposition (ALD) method. As for the liquid growth method, a self-assembly technology and a hydrothermal method are being suggested.
According to the conventional bottom-up method, nanoparticles are prepared in advance and then attached to a substrate having a modified surface. However, this method is limited because of nano-particle size constraints and nano-particle size distributions, which cause issues with memory reproducibility and reliability. In other words, with the method of fabricating nanostructures by simply attaching nanoparticles to a substrate, it is likely impossible to improve memory performance unless nanoparticle synthesis technology makes remarkable progress.
To overcome this limitation, nanoparticles may be prepared in a top-down method, such as lithography. However, the use of the top-down method requires a great deal of investment in equipment because a high-end lithography facility is needed. Moreover, since the process is quite complicated, mass-production ability is limited. Also, although the etch process is performed using an electron beam, it is difficult to keep the nanoparticle size under a predetermined level.